一次高原强降水过程的对流尺度集合预报试验及诊断分析  

Convective-scale ensemble forecast experiment and diagnostic analysis of a high-altitude heavy precipitation process

作　　者：刘侃 陈超辉 何宏让 姜勇强 LIU Kan;CHEN Chaohui;HE Hongrang;JIANG Yongqiang(College of Meteorology and Oceanography,National University of Defense Technology,Changsha 410073,China)

机构地区：[1]国防科技大学气象海洋学院,长沙410073

出　　处：《气象科学》2024年第5期847-856,共10页Journal of the Meteorological Sciences

基　　金：国家自然科学基金资助项目(42275169,42205045);湖南省自然科学基金资助项目(2022JJ30660)。

摘　　要：选取我国西南高原地区2014年5月9—10日一次致灾性强降水过程,利用GPM(Global Precipitation Measurement)卫星全球逐半小时降水实况数据和ERA5(ECMWF Reanalysis v5)等再分析资料,进行集合预报模拟、评估及机理分析。结果表明:(1)WRF模式较好地再现了此次高原强降水过程,基于BGM(Breeding Growth Mode)和LBGM(Local Breeding Growth Mode)初始扰动方法生成的集合平均预报对于此次高原强降水过程预报效果优于控制预报,且LBGM评估结果更优;(2)湿位涡的正压项MPV1和斜压项MPV2对强降水均有一定的指示意义,850 hPa MPV1负值区和MPV2正值区与降水雨带的落区、强度发展演变有较好的对应关系;(3)LBGM方案对于降水强度的改善优于BGM方案,原因之一在于LBGM方案对水汽通量散度和涡度的模拟更合理。The GPM(Global Precipitation Measurement)satellite data and ERA5(ECMWF Reanalysis v5)were used to perform ensemble forecast simulation,evaluation and diagnostic analysis on a severe precipitation event that occurred in the southwest plateau region of China on May 9-10,2014.Results found that the WRF model successfully reproduces the severe precipitation event,and the ensemble average forecast generated using the BGM(Breeding Growth Mode)and LBGM(Local Breeding Growth Mode)initial perturbation methods had better forecast accuracy than the control forecast,with the LBGM evaluation producing better results.The severe precipitation area was located in a region of high atmospheric moisture divergence and low-level convergence,and the distribution of negative vertical vorticity and positive vertical vorticity in the upper and lower levels of the atmosphere corresponded to the precipitation area.The study also identified the positive and tilted pressure of wet potential vorticity as having a certain indicative significance for severe precipitation,with the negative MPV1 region at 850 hPa and the positive MPV2 region corresponding well with the precipitation band and intensity development.The LBGM scheme exhibits superior improvement in rainfall intensity compared to the BGM scheme,primarily due to the more realistic simulation of water vapor flux divergence and vorticity in the LBGM scheme.

关 键 词：对流尺度集合预报 强降水成因 动力场诊断 机理分析 

分 类 号：P456.7[天文地球—大气科学及气象学]